Micro pump

ABSTRACT

There is provided a micro pump including a bottom substrate, a channel forming substrate coupled to the bottom substrate and provided with an inlet into which a fluid is introduced and an outlet through which the fluid is discharged, and a valve integrally formed with the channel forming substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Korean Patent Application No.10-2013-0034669 filed on Mar. 29, 2013, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a micro pump, and more particularly, toa micro pump repeatedly supplying an extremely small quantity of fluidand having a channel forming substrate and a valve integrally formedtherein.

2. Description of the Related Art

In order to develop new medicines and to perform experiments todetermine the stability thereof, it is essential to observe a reactionbetween new medicines (that is, drugs) and cells. In general, a reactionexperiment between the drug and the cell is performed using a culturedish or the like.

However, since reaction between drugs and the cells in experimentsperformed within the culture dish are very different from reactionsbetween drugs and cells in experiments performed within living bodies,it is difficult to accurately observe or inspect reactions between drugsand cells through only experimental results using culture dishes.Therefore, there is a need to develop new apparatuses allowing for theobservation of reactions between drugs and cells in an environmentsimilar to that of the interior of a living body.

To this end, the present inventors developed a technology forcirculating a culture medium. However, in order to smoothly culture thecell, there is a need to repeatedly supply an extremely small quantityof such a culture medium. To this end, a need exists for the developmentof a micro pump capable of repeatedly supplying an extremely smallquantity of fluid.

As related art regarding the micro pump, there are provided PatentDocuments 1 and 2. Patent Documents 1 and 2 relate to a technology formoving an extremely small quantity of fluid by a driving force of apiezoelectric element.

However, Patent Document 1 does not disclose a valve completelyinterrupting a flow of fluid, such that it may be difficult to deliver afixed quantity of fluid. In contrast, Patent Document 2 relates to atechnology for delivering a fixed quantity of fluid due to valvesrespectively disposed on respective upper substrates, but does notdisclose a structure in which a channel forming substrate and the valvesubstrates are integrally formed.

RELATED ART DOCUMENT

[Patent Document 1] KR 2008-070358 A

[Patent Document 2) JP 2000-249074 A

SUMMARY OF THE INVENTION

An aspect of the present invention provides a micro pump repeatedlysupplying an extremely small quantity of fluid and having a channelforming substrate and a valve integrally formed therein.

According to an aspect of the present invention, there is provided amicro pump, including: a bottom substrate; a channel forming substratecoupled to the bottom substrate and provided with an inlet into which afluid is introduced and an outlet through which the fluid is discharged;and a valve integrally formed with the channel forming substrate.

A first surface of the channel forming substrate may be provided withthe inlet and the outlet and a second surface of the channel formingsubstrate may be provided with a pressure chamber that connects theinlet to the outlet.

The micro pump may further include: an actuator formed on the firstsurface of the channel forming substrate and applying pressure to thepressure chamber.

The bottom substrate and the channel forming substrate may be formed ofsingle crystal silicon or silicon on insulator (SOI).

The upper substrate may be formed of a plastic or synthetic resinmaterial.

The micro pump may further include: an upper substrate coupled to thechannel forming substrate.

The upper substrate may be provided with a first hole connected to theinlet and a second hole connected to the outlet.

The valve may include: a thin film member; a first opening and closingmember formed by a first cut off line cutting off a portion of the thinfilm member; and a second opening and closing member formed by a secondcut off line cutting off another portion of the thin film member.

A length of the first cut off line may be longer than that of the secondcut off line.

The first cut off line may have a curved shape having a first radius andthe second cut off line may have a curved shape having a second radius.

The first radius and the second radius may have different sizes.

According to an aspect of the present invention, there is provided amicro pump, including: a bottom substrate; a channel forming substratecoupled to the bottom substrate and provided with an inlet into which afluid is introduced and an outlet through which the fluid is discharged;a vibration substrate coupled to the channel forming substrate; and avalve integrally formed with the channel forming substrate.

The channel forming substrate may be provided with the inlet, theoutlet, and a pressure chamber that connects the inlet to the outlet.

The micro pump may further include: an actuator formed on the firstsurface of the vibration substrate and applying pressure to the pressurechamber.

The bottom substrate, the channel forming substrate, and the vibrationsubstrate may be formed of single crystal silicon or silicon oninsulator (SOI).

The micro pump may further include: an upper substrate coupled to thechannel forming substrate.

The upper substrate may be provided with a first hole connected to theinlet and a second hole connected to the outlet.

The valve may include a thin film member; a first opening and closingmember formed by a first cut off line cutting off a portion of the thinfilm member; and a second opening and closing member formed by a secondcut off line cutting off another portion of the thin film member.

A length of the first cut off line may be longer than that of the secondcut off line.

The first cut off line may have a curved shape having a first radius andthe second cut off line may have a curved shape having a second radius.

The first radius and the second radius may have different sizes.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a cross-sectional view of a micro pump according to anembodiment of the present invention;

FIG. 2 is an enlarged view of part A illustrated in FIG. 1;

FIG. 3 is an enlarged view illustrating a method of operating a valveillustrated in FIG. 2;

FIG. 4 is an enlarged view of part B illustrated in FIG. 1;

FIG. 5 is an enlarged view illustrating a method of operating a valveillustrated in FIG. 4;

FIGS. 6 to 13 are diagrams illustrating another form of a valve; and

FIG. 14 is a cross-sectional view of a micro pump according to anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings. The invention may,however, be embodied in many different forms and should not be construedas being limited to the embodiments set forth herein.

Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventionto those skilled in the art.

FIG. 1 is a cross-sectional view of a micro pump according to anembodiment of the present invention and FIGS. 2 to 5 are enlarged viewsof parts A and B illustrated in FIG. 1.

A micro pump 100 according to an embodiment of the present inventionwill be described with reference to FIGS. 1 to 5.

The micro pump 100 according to the embodiment of the present inventionmay include a bottom substrate 110, a channel forming substrate 120, andan upper substrate 140. In addition, the micro pump 100 may furtherinclude an actuator 150, as needed. Herein, the bottom substrate 110,the channel forming substrate 120, and the upper substrate 140 may besequentially stacked.

The bottom substrate 110 may form a base part of the micro pump 100. Thebottom substrate 110 may be formed of single crystal silicon or siliconon insulator (SOI). In this case, the bottom substrate 110 may be astacked structure in which a silicon substrate and a plurality ofinsulating members are stacked.

The channel forming substrate 120 may be a substrate on which a channelthrough which a fluid (for example, a culture medium or a drug) isdelivered is formed. To this end, a first surface (an upper surface asviewed in FIG. 1) of the channel forming substrate 120 may be providedwith an inlet 122 and an outlet 124 and a second surface (a lowersurface as viewed in FIG. 1) may be provided with a pressure chamber126. Herein, the pressure chamber 126 may connect the inlet 122 to theoutlet 124 and may have a volume that may receive a predeterminedquantity of fluid.

Likewise the bottom substrate 110, the channel forming substrate 120 maybe formed of single crystal silicon or silicon on insulator (SOI). Thechannel forming substrate 120 formed as described above may be subjectedto a burning process so as to be integrally formed with the bottomsubstrate 110.

Valves 210 and 220 may be integrally formed with the channel formingsubstrate 120.

When a thickness of the valves 210 and 220 is the same as that of thechannel forming substrate 120, the number of processes is reduced, suchthat time and cost consumed in performing the process may be reduced.

In addition, when the thickness of the channel forming substrate 120 isthe same as that of the valves 210 and 220, an amount of force requiredto open and close the valves 210 and 220 may vary due to the thicknessof the channel forming substrate 120.

Therefore, the force required to open and close the valves 210 and 220may be controlled by controlling the thickness of the channel formingsubstrate 120.

The valves 210 and 220 may be formed in the inlet 122 and the outlet 124of the channel forming substrate 120, respectively, such that a fluidmay move in a single direction by forming.

The upper substrate 140 may be formed on one surface of the channelforming substrate 120 and may control a flow of fluid flowing in thechannel forming substrate 120.

The upper substrate 140 may be provided with a first hole 142 and asecond hole 144. Herein, the first hole 142 may be connected to theinlet 122 of the channel forming substrate 120 and the second hole 144may be connected to the outlet 124 of the channel forming substrate 120.

The valves 210 and 220 may be formed in the inlet 122 and the outlet124, respectively. In other words, the first valve 210 may be mounted inthe inlet 122 and the second valve 220 may be mounted at the outlet 124.Meanwhile, the embodiment of the present invention describes that thevalves are mounted at both of the inlet 122 and the outlet 124, but thevalve may be mounted only in one hole, as needed.

The upper substrate 140 may be formed of plastic or a synthetic resinmaterial. In this case, the upper substrate 140 is easily machined, andthus the manufacturing cost of the upper substrate 140 maybe saved.However, the upper substrate 140 may also be formed of the siliconsubstrate, as needed.

An actuator 150 may be formed on the channel forming substrate 120. Inother words, the actuator 150 may be formed on one surface (an uppersurface as viewed in FIG. 1) of the channel forming substrate 120. Theactuator 150 may be configured of a lower electrode, a piezoelectricelement, an upper electrode. In other words, the lower electrode may beformed on an upper surface of the channel forming substrate 120, thepiezoelectric element may be formed on an upper surface of the lowerelectrode, and the upper electrode may be formed on an upper surface ofthe piezoelectric element. The actuator 150 configured as describedabove may generate driving force in response to the deformation of thepiezoelectric element by current signals provided through the upperelectrode and the lower electrode. Herein, the driving force of theactuator 150 may be transferred to the pressure chamber 126 of thechannel forming substrate 120 to move a fluid.

Meanwhile, the micro pump 100 configured as described above may onlymove a fluid in a single direction through the valves 210 and 220.Portions associated therewith will be described with reference to FIGS.2 to 5.

An inlet side (a portion represented by A in FIG. 1) of the micro pump100 may be configured as illustrated in FIG. 2.

In other words, the inlet 122 of the channel forming substrate 120 mayhave a size of a first diameter D1 and the first hole 142 of the uppersubstrate 140 may have a size of a second diameter D2, thereby leadingto the circulation of the fluid in a single direction.

Herein, a first opening and closing member 20 and a second opening andclosing member 30 of the valve 210 have different areas, such that aforce (F1) applied to the first opening and closing member 20 and aforce (F2) applied to the second opening and closing member 30 aredifferent at all times even in the case that a uniform amount ofpressure is applied to the valve 210. Therefore, the first opening andclosing member 20 and the second opening and closing member 30 may haveinertia to be rotated in a single direction (a clockwise direction inFIG. 2) at all times.

However, when a difference (F1−F2) between the force (F1) applied to thefirst opening and closing member 20 and the force (F2) applied to thesecond opening and closing member 30 does not exceed a predeterminedreference force (for example, an elastic force of the valve 210), themembers 20 and 30 may be kept in a closed state (see FIG. 2).

A backflow prevention step 121 maybe formed on an upper portion of thefirst opening and closing member 20 of the valve 210 to prevent a fluidfrom backflowing.

In addition, the backflow prevention step 121 may be formed on a lowerportion of the second opening and closing member 30 of the valve 210 toprevent fluid from backflowing.

The backflow prevention step 121 may be formed by etching the channelforming substrate 120 stepwise and may also be formed by attaching aseparate attachment thereto.

When the backflow prevention step 121 is provided, the possibility ofthe backflow of fluid may be reduced.

In this state, when the difference (F1−F2) between the force (F1)applied to the first opening and closing member 20 and the force (F2)applied to the second opening and closing member 30 exceeds thepredetermined reference force due to the increase in a flux of fluid,the opening and closing members 20 and 30 may be rotated and thusopened, as illustrated in FIG. 3.

Meanwhile, the valve 210 according to the embodiment of the presentinvention may prevent the opening and closing members 20 and 30 fromshaking severely and may be rapidly opened and closed in response to achange in the flux of fluid, even in the case that the flow of fluid isirregular, since the rotation of the opening and closing members 20 and30 is performed in the vicinity of a central point of a thin film member10.

Further, the valve 210 according to the embodiment of the presentinvention may control the opening and closing conditions of the openingand closing members 20 and 30 based on the area of the opening andclosing members 20 and 30, and thus may also control an extremely smallquantity of flux.

Further, based on torsion, it is determined whether the valve 210 isopened or closed, and an amount of force required to open and close thevalve may be controlled by controlling the thickness of the channelforming substrate 120.

Further, in the valve 210, a difference between radii of the first andsecond cut off lines (40 and 50) may be controlled to thus control forcerequired to open and close the valve.

In addition, a resonance frequency of the valve 210 is the same as adriving frequency of the actuator 150 by controlling a differencebetween radii of the first and second cut off lines 40 and 50 of thevalve 210, such that the valve 210 may be controlled to be easily openedand closed at the driving frequency of the actuator 150.

An outlet side (a portion represented by B in FIG. 1) of the micro pump100 may be configured as illustrated in FIG. 4.

In other words, the outlet 124 of the channel forming substrate 120 mayhave a size of a third diameter D3, and the second hole 144 of the uppersubstrate 140 may have a size of a fourth diameter D4, thereby leadingto the circulation of the fluid in a single direction.

Herein, the first opening and closing member 20 and the second openingand closing member 30 of the valve 220 have different areas, such thatthe force (F1) applied to the first opening and closing member 20 andthe force (F2) applied to the second opening and closing member 30 aredifferent at all times even in the case that uniform pressure is appliedto the valve 220. Therefore, the first opening and closing member 20 andthe second opening and closing member 30 may have inertia to be rotatedin a single direction (a clockwise direction in FIG. 3) at all times.

However, when a difference (F1−F2) between the force (F1) applied to thefirst opening and closing member 20 and the force (F2) applied to thesecond opening and closing member 30 does not exceed a predeterminedreference force (for example, an elastic force of the valve 220), themembers 20 and 30 may be kept in a closed state (see FIG. 3).

The backflow prevention step 121 may be formed on the lower portion ofthe first opening and closing member 20 of the valve 220 to prevent afluid from backflowing.

In addition, the backflow prevention step 121 may be formed on the upperportion of the second opening and closing member 30 of the valve 220 toprevent a fluid from backflowing.

The backflow prevention step 121 may be formed by etching the channelforming substrate 120 stepwise and may also be formed by attaching aseparate attachment thereto.

When the backflow prevention step 121 exists, the possibility of thebackflow of fluid may be reduced.

In this state, when the difference (F1−F2) between the force (F1)applied to the first opening and closing member 20 and the force (F2)applied to the second opening and closing member 30 exceeds thepredetermined reference force due to the increase in a flux of fluid,the opening and closing members 20 and 30 may be rotated and thusopened, as illustrated in FIG. 5.

Meanwhile, the valve 220 according to the embodiment of the presentinvention may prevent the opening and closing members 20 and 30 fromshaking severely and may be rapidly opened and closed in response to achange in the flux of fluid, even in the case that the flow of fluid isirregular, since the rotation of the opening and closing members 20 and30 is performed in the vicinity of a central point of the thin filmmember 10.

Further, in the valve 220 according to the embodiment of the presentinvention, the opening and closing conditions of the opening and closingmembers 20 and 30 may be controlled based on the area of the opening andclosing members 20 and 30, and thus, an extremely small quantity of fluxmay be adjusted.

Further, based on torsion, it is determined whether the valve 220 isopened or closed and force required to open and close the valve may becontrolled by controlling the thickness of the channel forming substrate120.

Further, in the valve 220, a difference between radii of the first andsecond cut off lines 40 and 50 may be controlled to thus control forcerequired to open and close the valve.

That is, a resonance frequency of the valve 220 is the same as a drivingfrequency of the actuator 150 by controlling a difference between radiiof the first and second cut off lines 40 and 50 of the valve 220, suchthat the valve 220 may be controlled to be easily opened and closed atthe driving frequency of the actuator 150.

Further, since in the micro pump 100, the valves 210 and 220 may beintegrally formed with the channel forming substrate 120, themanufacturing process of the micro pump 100 may be simplified and themanufacturing costs thereof may be saved.

Next, another form of the valve will be described with reference toFIGS. 6 to 13. First, the valves 210 and 220 according to a firstembodiment of the present invention will be described with reference toFIGS. 6 to 8.

The valves 210 and 220 according to the first embodiment of the presentinvention may include the thin film member 10, the first opening andclosing member 20, and the second opening and closing member 30. Herein,the thin film member 10, the first opening and closing member 20, andthe second opening and closing member 30 may be integrally formed. Inother words, the first opening and closing member 20 and the secondopening and closing member 30 may be formed by machining the thin filmmember 10.

The thin film member 10 may be a membrane having a circularcross-section. However, a cross-sectional shape of the thin film member10 is not limited to a circle. For example, the thin film member 10 mayhave a polygonal cross-section, including a quadrangular shape.

The thin film member 10 may be formed of an elastic material. In otherwords, the thin film member 10 may be formed of a material that may bewarped or deformed when a predetermined amount of force is appliedthereto. For example, the thin film member 10 may be formed of amaterial, such as plastic, rubber, synthetic resin, metal, or the like.However, a material of the thin film member 10 is not limited only tothe listed materials, and therefore the thin film member 10 may beformed of any material having a predetermined degree of elastic force.

The first opening and closing member 20 may be formed in one portion ofthe thin film member 10. In other words, the first opening and closingmember 20 may be formed on the upper portion of the thin film member 10by the first cut off line 40. Herein, the first cut off line 40 may be acurved line having a first radius R1. In this case, the first openingand closing member 20 may have an approximately semi-circular shape.However, the shape of the first opening and closing member 20 and thefirst cut off line 40 is not limited to a shape illustrated in FIG. 6.For example, the first opening and closing member 20 may have arectangular or squared shape and the first cut off line 40 may beconfigured of a plurality of straight lines, rather than as curvedlines, as illustrated in FIGS. 7 and 8.

The first opening and closing member 20 may be opened and closed basedon a horizontal line segment L-L. For example, the first opening andclosing member 20 may be rotated based on the horizontal line segmentL-L. Herein, the rotation direction of the first opening and closingmember 20 may be changed according to the mounting position of thevalves 210 and 220.

The second opening and closing member 30 may be formed in one portion ofthe thin film member 10. In other words, the first opening and closingmember 30 may be formed on the lower portion of the thin film member 10by the second cut off line 50. Herein, the second cut off line 50 may bea curved line having a second radius R2. In this case, the secondopening and closing member 30 may have an approximately semi-circularshape. However, the shape of the second opening and closing member 30and the second cut off line 50 is not limited to a shape illustrated inFIG. 6. For example, the second opening and closing member 30 may have arectangular or squared shape and the second cut off line 50 may beconfigured of a plurality of straight lines, rather than a curved line,as illustrated in FIGS. 7 and 8.

The second opening and closing member 30 may be opened and closed basedon the horizontal line segment L-L, like the first opening and closingmember 20. For example, the second opening and closing member 30 may berotated based on the horizontal line segment L-L. Herein, the rotationdirection of the second opening and closing member 30 may be opposite tothe rotation direction of the first opening and closing member 20. Forexample, when the first opening and closing member 20 is openedforwardly, the second opening and closing member 30 may be openedbackwardly and when the first opening and closing member 20 is openedbackwardly, the second opening and closing member 30 may be openedforwardly.

The first opening and closing member 20 and the second opening andclosing member 30 may respectively have a predetermined area. In otherwords, the first opening and closing member 20 may have a first area A1and the second opening and closing member 30 may have a second area A2.Herein, the first area A1 of the first opening and closing member 20 maybe larger than the second area A2 of the second opening and closingmember 30. To this end, a length of the first cut off line 40 may belonger than that of the second cut off line 50. Alternatively, the firstradius R1 of the first cut off line 40 may be larger than the secondradius R2 of the second cut off line 50.

As such, when the area of the first opening and closing member 20 andthe area of the second opening and closing member 30 are formeddifferently, the magnitude of the force applied to the first opening andclosing member 20 and the second opening and closing member 30 may bedifferent. This may concentrate force on the first opening and closingmember 20, such that the rotation (that is, opening) of the firstopening and closing member 20 may be induced. Herein, the first openingand closing member 20 and the second opening and closing member 30substantially move integrally, such that the rotation of the firstopening and closing member 20 may also induce the rotation of the secondopening and closing member 30. Therefore, according to the embodiment ofthe present invention, the flow of fluid may be controlled by opening orclosing the first opening and closing member 20 and the second openingand closing member 30 simultaneously.

Meanwhile, a difference in the areas of the first opening and closingmember 20 and the second opening and closing member 30 may be changedaccording to the magnitude of the elastic force of the thin film member10. For example, when the elastic force of the thin film member 10 isrelatively large, the difference in the areas of the first opening andclosing member 20 and the second opening and closing member 30 may belarge, and when the elastic force of the thin film member 10 isrelatively small, the difference in the areas of the first opening andclosing member 20 and the second opening and closing member 30 may berelatively small. The reason is that only when the force depending onthe difference in the areas of the first opening and closing member 20and the second opening and closing member 30 is large than the elasticforce of the thin film member 10, the opening and closing members 20 and30 may be rotated.

For reference, in the embodiment of the present invention, both ends ofthe first cut off line 40 and both ends of the second cut off line 50may be located on the horizontal line segment L-L passing through acentral point O. In this case, rotating reference points of the firstopening and closing member 20 and the second opening and closing member30 are located on the same line, such that the simultaneous rotation ofthe first opening and closing member 20 and the second opening andclosing member 30 may be smoothly performed.

In the valves 210 and 220 configured as described above, the openingconditions of the opening and closing members 20 and 30 may be set byforming the first opening and closing member 20 and the second openingand closing member 30 to have different sizes. Therefore, even in thecase of a pipe through which an extremely small quantity of fluid moves,the flow of fluid may be effectively controlled by controlling thedifference in the areas of the first opening and closing member 20 andthe second opening and closing member 30.

Next, the valves 210 and 220 according to a second embodiment of thepresent invention will be described with reference to FIGS. 9 to 11.

The valves 210 and 220 according to the second embodiment of the presentinvention may be differentiated from the first embodiment of the presentinvention in that heights from the central point O of the thin filmmember 10 to apexes of the cut off lines 40 and 50 are different. Thatis, a height h1 from the central point O to the apex of the first cutoff line 40 maybe different from a height h2 from the central point O tothe apex of the second cut off line 50.

The structure may naturally induce the difference in the areas of thefirst opening and closing member 20 and the second opening and closingmember 30. In addition, in the structure, a portion of separating bothends of the first cut off line 40 and the second cut off line 50 servesas a rotation shaft, such that the first opening and closing member 20and the second opening and closing member 30 may be smoothly rotated.

Meanwhile, the shape of the first opening and closing member 20 and thesecond opening and closing member 30 may be changed as illustrated inFIGS. 10 and 11. To this end, the first cut off line 40 and the secondcut off line 50 may be configured of a plurality of straight lines.

Next, a valve according to third and fourth embodiments of the presentinvention will be described with reference to FIGS. 12 and 13.

The third and fourth embodiments of the present invention may bedifferentiated from the above-mentioned embodiments in that the valves210 and 220 include a third cut off line 60 and a fourth cut off line70.

The valves 210 and 220 according to the third embodiment of the presentinvention may further include the third cut off line 60. The third cutoff line 60 may extend inwardly (in a direction toward the central pointO) from both ends of the first cut off line 40. The third cut off line60 is not connected to the second cut off line 50, but may be located onthe same line as both ends of the second cut off line 50.

In the valves 210 and 220 formed as described above, a connection lengthL1 between the thin film member 10 and the first opening and closingmember 20 is relatively short by the third cut off line 60, such thatthe motion of the first opening and closing member 20 may be smoothlyperformed.

The valves 210 and 220 according to the fourth embodiment of the presentinvention may further include the third cut off line 60 and the fourthcut off line 70. The third cut off line 60 may extend inwardly from bothends of the first cut off line 40 and the fourth cut off line 70 mayextend outwardly from both ends of the second cut off line 50. Herein,both ends of the first cut off line 40 and both ends of the second cutoff line 50 are formed at a predetermined distance, and thus the thirdcut off line 60 and the fourth cut off line 70 may not be connected toeach other.

In the valves 210 and 220 formed as described above, a shaft 16 that isa rotation reference of the first opening and closing member 20 and thesecond opening and closing member 30 is formed by the third cut off line60 and the fourth cut off line 70, such that the first opening andclosing member 20 and the second opening and closing member 30 may besmoothly rotated.

Next, a micro pump 100 according to another embodiment of the presentinvention will be described with reference to FIG. 14. For reference, inthe present embodiment, the same reference numerals will be used todescribe the same components as those of the above-mentioned embodimentand a detailed description of these components will be omitted.

The micro pump 100 according to the present embodiment may bedifferentiated from the above-mentioned embodiment in terms of thechannel forming substrate 120 and a vibration substrate 130.

Similarly to the above-mentioned embodiment, the channel formingsubstrate 120 may include the inlet 122, the outlet 124, and thepressure chamber 126. However, in the present embodiment, the pressurechamber 126 may have a shape completely opened in a vertical direction,differently from the above-mentioned embodiment. The pressure chamber126 having the shape may be easily formed in an etching process (inparticular, a wet etching process), and the size and volume of thepressure chamber 126 may be easily changed by controlling the thicknessof the channel forming substrate 120.

The vibration substrate 130 may be coupled to the channel formingsubstrate 120. The vibration substrate 130 may be formed of singlecrystal silicon or silicon on insulator (SOI). The vibration substrate130 may be provided with through holes 132 and 134. Herein, the firstthrough hole 132 may connect the inlet 122 with a first hole 142, andthe second through hole 134 may connect the outlet 124 with a secondhole 144.

In the micro pump 100 configured as described above, the channel formingsubstrate 120 may be easily manufactured through the etching process. Inaddition, the vibration substrate 130 is separately manufactured, andtherefore the slimness of the vibration substrate 130 is easilyimplemented, such that power consumption required to drive the actuator150 may be reduced.

As set forth above, according to the embodiment of the presentinvention, the fluid including the micro material in a micro unit may beeffectively delivered.

Further, according to the embodiment of the present invention, thechannel forming substrate and the valve may be integrally formed in themicro pump, thereby simplifying the manufacturing process of the micropump and saving the manufacturing process costs.

While the present invention has been shown and described in connectionwith the embodiments, it will be apparent to those skilled in the artthat modifications and variations can be made without departing from thespirit and scope of the invention as defined by the appended claims.

What is claimed is:
 1. A micro pump, comprising: a bottom substrate; achannel forming substrate coupled to the bottom substrate and providedwith an inlet into which a fluid is introduced and an outlet throughwhich the fluid is discharged; and a valve integrally formed with thechannel forming substrate.
 2. The micro pump of claim 1, wherein a firstsurface of the channel forming substrate is provided with the inlet andthe outlet, and a second surface of the channel forming substrate isprovided with a pressure chamber that connects the inlet to the outlet.3. The micro pump of claim 2, further comprising: an actuator formed onthe first surface of the channel forming substrate and applying pressureto the pressure chamber.
 4. The micro pump of claim 1, wherein thebottom substrate and the channel forming substrate are formed of singlecrystal silicon or silicon on insulator (SOI).
 5. The micro pump ofclaim 1, further comprising: an upper substrate coupled to the channelforming substrate.
 6. The micro pump of claim 5, wherein the uppersubstrate is provided with a first hole connected to the inlet and asecond hole connected to the outlet.
 7. The micro pump of claim 1,wherein the valve includes: a thin film member; a first opening andclosing member formed by a first cutting line cutting a portion of thethin film member; and a second opening and closing member formed by asecond cutting line cutting another portion of the thin film member. 8.The micro pump of claim 7, wherein a length of the first cut off line islonger than that of the second cut off line.
 9. The micro pump of claim7, wherein the first cut off line has a curved shape having a firstradius, and the second cut off line has a curved shape having a secondradius.
 10. The micro pump of claim 9, wherein the first radius and thesecond radius have different sizes.
 11. A micro pump, comprising: abottom substrate; a channel forming substrate coupled to the bottomsubstrate and provided with an inlet into which a fluid is introducedand an outlet through which the fluid is discharged; a vibrationsubstrate coupled to the channel forming substrate; and a valveintegrally formed with the channel forming substrate.
 12. The micro pumpof claim 11, wherein a first surface of the channel forming substrate isprovided with the inlet and the outlet, and a second surface of thechannel forming substrate is provided with a pressure chamber thatconnects the inlet to the outlet.
 13. The micro pump of claim 12,further comprising: an actuator formed on the first surface of thechannel forming substrate and applying pressure to the pressure chamber.14. The micro pump of claim 11, wherein the bottom substrate and thechannel forming substrate are formed of single crystal silicon orsilicon on insulator (SOI).
 15. The micro pump of claim 11, furthercomprising: an upper substrate coupled to the channel forming substrate.16. The micro pump of claim 15, wherein the upper substrate is providedwith a first hole connected to the inlet and a second hole connected tothe outlet.
 17. The micro pump of claim 11, wherein the valve includes:a thin film member; a first opening and closing member formed by a firstcut off line cutting off a portion of the thin film member; and a secondopening and closing member formed by a second cut off line cutting offanother portion of the thin film member.
 18. The micro pump of claim 17,wherein a length of the first cut off line is longer than that of thesecond cut off line.
 19. The micro pump of claim 17, wherein the firstcut off line has a curved shape having a first radius, and the secondcut off line has a curved shape having a second radius.
 20. The micropump of claim 19, wherein the first radius and the second radius havedifferent sizes.